I finally seem to have found an ideal Mario Galaxy setup... with a small issue. For whatever reason, all of the rooms that you use to get to the galaxies (i.e. Terrace, Kitchen, etc.) turn black when I walk inside of them (except on a rare occasion where they'll display correctly... by rare I mean it happened once.) Also, on Beach Bowl galaxy, ALL effects have turned into black boxes (such as Mario's spin, the water effects, the star bits.) What could be causing this?

Try using builds from 4.0 or above first. When you configure Dolphin, try to use as few of those hacks you mentioned as possible. Lastly, could you post a screenshot of the issue? Do OpenGL and D3D11 work properly, or are they broken as well? You only mentioned that they are running slow, so I figured I'd ask.

They went away when I played today :O my only issue now is the occasional moment where the game will sort of pause and loop whatever just happened very quickly. It doesn't happen too often as to make the game unplayable, but enough that it's annoying :\

Now, why is it that OpenGL with vertex streaming hack simply won't run as lightning fast as DX9? It would seem that with my GPU it would, but it just won't.

Does audio backend have anything to do with it? Is there a certain backend that seems to work better on SMG?